// 演示与用户交互
#include <stdio.h>
#include <string.h> //strlen()函数原型
#define DENSITY 62.4 //人体密度
int main(void)
{
    float weight, volume;
    int size, letters;
    char name[40]; //一个可容纳40字符的数组

    printf("Hi! What's your first name?\n");
    scanf("%s", name);
    printf("%s, what's your weight in pounds?\n",name);
    scanf("%f", &weight);
    size = sizeof name;
    letters = strlen(name);
    volume = weight / DENSITY;
    printf("Well, %s, your volume is %2.2f cubic feet.\n", letters);
    printf("and we have %d bytes to store it.\n", size);

    return 0;
}